The disclosure is directed to softproofing, i.e., reviewing an electronic representation of an image prior to printing, copying, or otherwise producing the image on a media, such as a sheet of paper. In particular, exemplary embodiments of the disclosure identify specific internal rendering characteristics of a target printer and model the electronic representation for display on a monitor so as to faithfully represent the appearance of a resultant hardcopy printout, for example, of a document on a printer.
An important part of many digital print workflows is customer softproofing, which provides a preview display on the customer's display monitor of a projected hardcopy printer output from a target print engine. However, for softproofing to be beneficial, there must be an accurate representation of the ultimate printed results. Generally, softproofing begins with an electronic file containing one or more objects representing one or more pages of print data, which is converted to be displayed on an image display device, such as a monitor. Customers can learn how the electronic file will look without actually printing out the document. Thus, softproofing can save customers from unnecessarily using resources such as toner and paper.
The electronic file can be obtained from several sources, for example: i) capturing by a scanning device; ii) outputting from a print controller decomposition service; iii) importing from another application program, or iv) generating by an application program, such as Microsoft Word, Adobe Acrobat, or Microsoft PowerPoint.
The softproofing may begin with an image in a raster image format. The raster images represent image data as a sequence of pixels using a single bit or multiple bits per pixel. Image files may also be contained in, for example, TIFF files or in page description language (PDL) files such as, for example, Adobe Portable Document Format (PDF) files. Using various lossless compression algorithms, the binary image files, for example, may be relatively small, but able to support high image quality. Print controllers may process such raster images at rates of hundreds of pages per minute. For these reasons, raster images are widely used throughout the printing industry.
A raster image is created by assembling multiple scan lines across the page. Each scan line is represented by numerous pixels or dots. Raster images can be device independent or device dependent. On the one hand, device dependent images are targeted to a specific image output device, such as a specific print engine. On the other hand, device independent images are not targeted to a specific image output device.
Present monochrome raster image path architectures commonly represent print jobs in terms of pages of device dependent binary raster images, typically formatted as TIFF 6.0 CCITT Group IV images. Scanners initially capture each page as a device independent grayscale image having multiple bits per pixel and then immediately convert the result into a device dependent binary raster image (one bit per pixel) targeted for output on a specific print engine. Because the characteristics of each print engine vary, so too will the device dependent binary raster images targeted for them. Such characteristics can include whether the print engine writes white or black, minimal permissible line width, a specific tone reproduction curve (TRC), one or more available halftone screens, halftone dot patterns, and the use of error diffusion to minimize Moiré effects to best render a raster image for a particular print engine. In a process known as segmentation, following scanning, images are analyzed into different regions, each of which can be rendered so as to print optimally on the intended target print engine.
Current softproofing programs are based on raster images, but the programs are limited in usefulness as they only provide a reasonable representation of what an electronic file will look like when printed. Existing softproofing programs either do not try to accurately represent all aspects of objects as they would actually appear when rendered by a specific target print engine or are incapable of such representation. Instead, existing softproofing programs are ordinarily intended for representing features like the layout of the document, imposition arrangements, or appropriate color rendering. For example, Microsoft Word's print preview feature focuses on providing printed page layout information, but does not accurately portray exactly how the document itself will look printed from the printer. Similarly, softproofing applications such as Integrated Color Solutions' Remote Director, ORIS' Soft Proof, Kodak Matchprint Virtual Proofing (formerly KPG Matchprint), EFI's Fiery Graphic Arts Package, and the like focus on certain color rendering modifications for the softproofing, but do not address various print engine specific rendering characteristic adjustments.